Have been booting proxmox machines off ZFS for a few years now, and the only bad experiences have been with grub. Troubleshooting at the intersection of grub and ZFS is..., well..., giving up and reinstalling is usually quicker. So I'm hopeful that Ubuntu's focus on ZFS boot will eventually lead to some of these issues being ironed out.
Does the ubuntu kernel also comes with the patch that enables vectorized cpu extensions/AVX/AES-NI for zfs these days? <a href="https://www.phoronix.com/scan.php?page=news_item&px=NixOS-Linux-5.0-ZFS-FPU-Drop" rel="nofollow">https://www.phoronix.com/scan.php?page=news_item&px=NixOS-Li...</a>